Benato / Paolucci EHV AC Undergrounding Electrical Power

Performance and Planning
1. Auflage 2010
ISBN: 978-1-84882-867-4
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 175 Seiten, eBook

Reihe: Power Systems

"EHV AC Undergrounding Electrical Power" discusses methods of analysis for cable performance and for the behaviour of cable, mixed and overhead lines.The authors discuss the undergrounding of electrical power and develop procedures based on the standard equations of transmission lines. They also provide technical and economical comparisons of a variety of cables and analysis methods, in order to examine the performance of AC power transmission systems. A range of topics are covered, including: energization and de-energization phenomena of transmission lines; power quality; and cable safety constraints."EHV AC Undergrounding Electrical Power" is a guide to cable insertion planning and the operation of power networks. It will enable readers to make performance comparisons between power transmission systems, which will be valuable for postgraduates, as well as engineers involved in power cable manufacturing or electrical transmission systems.

Zielgruppe

Research

Autoren/Hrsg.

Benato, Roberto

Paolucci, Antonio

Inhaltsverzeichnis

HV Cable World Statistics and some Large Installations.- The Positive Sequence Model of Symmetrical Lines.- Operating Capability of Long AC EHV Power Cables.- Operating Capability of AC EHV Mixed Lines with Overhead and Cables Links.- Multiconductor Analysis of UGC.- A Comparative Procedure for AC OHL and UGC Overall Cost.

Leseproben

"Chapter 4 Operating Capability of AC EHV Mixed Lines with Overhead and Cables Links (p. 89-90)

4.1 Introduction

The previous chapter has been devoted to the operating capability and constraints involved in power transmission of long AC cable links. In this chapter the approach has been extended in order to show the transmission performance of some typical mixed configurations with overhead lines (OHL) and underground cable lines (UGC). In order to erect a new long link, (but also, often, to fit an existing one due to new territory necessities) it could be necessary to have a mix of transmission technologies such as a cascade connection of OHL–UGC–OHL. In fact, the overhead line can be unsuitable in certain parts of the route for tackling some environmental and orographical problems, which can be easily overcome with (as already stated in Chapter 3) UGCs.

For example, an UGC section allows a HV/EHV link to pass inside galleries or through areas too wide for OHL span such as large lakes or arms of the sea: it is sometimes called a “siphon”. This configuration may also solve some critical issues, due to strong local oppositions or some laws, since it drastically reduces the environmental and magnetic impacts and hence it permits the UGC line to pass through or near a protected site (sensible places such as a school or natural park) or an urbanized area also with economical convenience (see Chapter 6).

It is worth remembering that some important installations of mixed OHL–UGC links have been realized for several years to allow great power flows towards town centres. It must be emphasized that the use of UGCs gives usually the economic burden of the shunt compensation reactors. For the aforementioned reasons, the transmission system operators will have to face more and more the analysis of mixed lines aiming at achieving their possible performances without jeopardizing the system safety and the power quality.

4.2 Mixed Lines: OHL–UGC–OHL

A rigorous approach to the issue requires to fix, for each OH and UG section, the specified constraints regarding the safety and the lifetime of section itself and to research successively the maximum compatible performances of the whole link. A simpler approach [1] can be adopted when the situation is that of Figure 4.1 (? OHL–? UGC–? OHL, with lengths d1, d2, and d3/, where the intermediate section is constituted of UGC: in this (very usual) case the steady state constrains expressed by (4.1) and (4.2), analogous to (3.1) and (3.2), appear sufficient to satisfy the ampacity not only of the cable but also of OHL ? and ?."

Über Autor(innen)

Roberto Benato was born in Venezia, Italy, in 1970. He received his Dr.-Ing. degree in Electrical Engineering from the University of Padova in 1995 and his PhD in Power Systems Analysis in 1999. In 2002 he was appointed Assistant Professor in the Power System Group in the Department of Electrical Engineering at the University of Padova. His main fields of research are multiconductor analysis, EHV-HV transmission lines and advanced matricial techniques for static and dynamic power system analysis. He is a member of CIGRÉ WG B1.08 "Cable systems in multipurpose or shared structures", secretary of CIGRÉ JWG B3-B1.09 "Application of Long High Capacity Gas Insulated Lines in Structures" and a member of the IEEE PES Substations Committee. He is also a member of IEEE and the Italian AEIT. Antonio Paolucci was born in Padova, Italy, in 1924. He received his Dr.-Ing. degree in Electrical Engineering from the University of Padova in 1950. He joined the Department of Electrical Engineering at the University of Padova in 1952 where he was Assistant and later Associate Professor. From 1973 to 2000 he was Full Professor of Power Systems Analysis. At present, he participates in the Power System Research Group of the University of Padova and is a member of AEIT.